Pipe for the conveyance of fluids.



E. H PORTER.

PIPE FOR THE CONVEYANCE OF F-LUIDS.

APPLICATION FILED FEB. I0. I9I4.

1,218,895. Patented Mar. 13, 1917.

' i'i-x v UNITED STATES FATE onmon.

EDWIN H. PORTEIQOF PHILADELPHIA, PENNSYLVANIA.

PIPE FOR THE CONVEYANCE FLUIDS.

specification of Letters Patent.

Patented Mar. 13, 19171 Application filed February 10, 1914. Serial No.817,818.

ticularly to pipes for the conveyance of liquids and gases at atemperature diflering from that of the surrounding medlum, and

specifically to a construction'of such pipes whereby the fiow of heatbetween the liquid or gas inside the pipe, to or from the externalsurrounding medium, is reduced to a minimum.

It is well known in the art that a space of high vacuum interposedbetween adjacent opposed surfaces, is a very effective means ofpreventing the transfer of heat between the two surfaces, and myinvention consists in such a construction of pipes as to provide the twowalls, separated by. a vacuum space throughout their length, and sojoined at their adjacent ends as to be solid and permanentlyair tight.

I have also arranged to avoid undue strains being set up in the twowalls due to unequal expansion or contraction of the walls, due to theunequal temperature of the two.

In the application of my invention I contemplate using standard metalpipe fittings or lengths of tubing in commercial lengths,

as used in the art, of difl'eren t diameters;'- placing same inconcentric positioneach to.

the other, swaging in one, or both, a surface off-set bend in the'shortlengths, and in the longer lengths two or more combined surface off-setbends or corrugations, and sol idly welding the adjacent ends of thetubes together, forming an included space, then exhausting this space toa high vacuum through a small outlet provided, and closing the outlet bysealing or welding. Recent development in the art of swaging and weldingmetal plates make this construction commercially practicable and thusmakes possible'the maintaining of a vacuum chamber between the two wallsthat is per manent in character. f p

The off-set surface bends or corrugations in the metal also produce alengthened path of the metal heat-conducting circuit, between the innerand outer walls diminishing the rate of transfer of heat through theconducting metal at the junction of the walls and thusreduces the partof the total length of pipe that requires protecting with externalnon-conducting material.

The completed units are joined up in any of the standard commercialmethods to comprise a. complete system for distributing liqu1ds andgasesWltll a minimum change in I, the temperature of same.

The above construction is of value in pip- I ing the high temperaturesuper-heated steam in modern power houses, in under-ground steam heatingsystems, in refrigerating plants for conveying the cold gases or brineand many other similar operations where 7 heat insulation is requireReferring to the drawings, Figure 1 shows a section through a pipe soconstructed, arranged for coupling by means of external flanges. Fig. 2shows in section a similarly arranged pipe fitted'with an externalthread connection. Fig. 3 shows in section a similar pipe arranged withan internal thread connection such as would couple to the pipe shown inFig. 2 for joining same in continuous lengths.

Fig. 4 shows in section a 90 bend of the same construction. I

Many other styles of application .of the same construction could beshown but the above are sufficient'to show the application of ourconstruction-to all standard pipe requirement. r

Ineach figure of the drawings W indicates the point of the solidmetallic jointor weld, of the metal tubing walls M is the metal tubing.V is the vacuum space.

S is the sealing-oil tube. bend or corrugation in the metal tube M.

Having thus shown and described my in-' vention, what I claim as new andwish to protect by Letters Patent of the .United- States is set forth inthe following claims:

1. An integral-unit for pipes for conveying fluids with a minimum ofheat transference between the interior bore or passage of the pipe andthe exterior, comprising a duplex tubular metallic casing havingimperforate inner and outer walls inclosing an exhausted or vacuumannular space extending substantially throughout the length thereof,said walls beingunited at the ends into a single wall, and havingcorrugations O is the off-set adjacent the union of the Walls at eachend to accommodate the variations in the expansion of the walls andrelieve the strains at the points of union between the inner and outerwalls of the duplex casing.

2. An integral unit for pipes for conveyfluids with a minimum of heattransfer-.

ence between the interior bore or-passage of the \pipe andthe exterior,comprisinga duplex tubular metallic casing having imperforate inner andouter walls inclosing an exhausted or vacuum annular space extendingsubstantially throughout the length thereof. said inner and outer wallsbeing weldedat each end into single end portions, the outer wall havingcorrugations at each end adjacent the weld union to thereby relieve thel strains at this point caused by the variations in expansion betweenthe inner and outer walls. e v

3. An integral unit for pipes for conveysaid inner and outer walls beingwelded at.

each end into single end portions, the one of said walls havingcorrugations therein to thereby relieve the strains at the points of.union of the inner and outer walls caused by the variations inexpansion between the inner and outer walls.

In testimony whereof I affix my signature in presence of two witnesses.

V EDWIN H. PORTER.

Witnesses: I v l L1 EMMA D. CHAPPELL, JOSEPH B. SEAMAN.

